The invention relates to tube sealing devices and more particularly to tube sealing devices for sealing flexible tubing.
Known tube sealing devices are used to seal flexible tubing. As one example, the sealing device is used to seal flexible tubing used in a disposable manifold system of a filling apparatus. Filling apparatus are commonly used in pharmaceutical, biomedical, chemical, and food packaging industries. The disposable manifold system includes multiple containers, typically bags, connected by a series of respective, discrete fill tubes that branch off from a main supply tube. The main supply tube is connected to a reservoir containing a fluid. After the manifold system is connected to the reservoir, fluid is pumped from the reservoir into the main supply tube, through the fill tubes, and into the bags thereby filling the bags with fluid. The bags can be filled simultaneously or sequentially with the use of clamps or valves to selectively direct flow through only desired fill tubes and desired portions of the main supply tube. After a bag is filled, it is removed from the manifold system by heat sealing the corresponding fill tube and then cutting the fill tube from the manifold system at a location above the seal. Manifold systems are disposable to avoid the cleaning, sterilizing, and validating issues prevalent when using non-disposable fill systems.
Generally, tube sealing devices include a sealing tool that is positioned on a pneumatic press for manipulation of the sealing tool between open and closed positions. In the open position, upper and lower heads are positioned adjacent each other and in the closed position, the upper and lower heads are separated a greater distance from each other. Each of the upper and lower heads is capable of being alternately heated and cooled.
To seal a tube, flexible tubing is positioned across the sealing tool when the tool is in the open position. The upper and lower heads are heated to an elevated temperature and then the press moves the heads to the closed position to sandwich a portion of the tube between the heads. The upper and lower heads transfer heat and apply pressure to the portion of the tube in contact with the heads. After a time sufficient to allow the heat of the heads to pass through the sandwiched portion of the tube, the upper and lower heads no longer generate heat and begin to cool, either with active or passive cooling, while remaining in contact with the tube. As the tube cools with the upper and lower heads, the inside walls of the heated portion of the tube bond together thereby creating a seal in the tube. Once adequately cooled, the press opens the tool to separate the heads allowing the sealed tube to be removed from the tool. The seal in the tube restricts flow through the tube.